cosmetics: add some documentation to FLACContext

Originally committed as revision 16881 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/flacdec.c

@@ -58,16 +58,16 @@ enum decorrelation_type {
 typedef struct FLACContext {
     FLACSTREAMINFO
 
-    AVCodecContext *avctx;
-    GetBitContext gb;
+    AVCodecContext *avctx;                  ///< parent AVCodecContext
+    GetBitContext gb;                       ///< GetBitContext initialized to start at the current frame
 
-    int blocksize/*, last_blocksize*/;
-    int curr_bps;
+    int blocksize;                          ///< number of samples in the current frame
+    int curr_bps;                           ///< bps for current subframe, adjusted for channel correlation and wasted bits
     int sample_shift;   /* shift required to make output samples 16-bit or 32-bit */
     int is32;           /* flag to indicate if output should be 32-bit instead of 16-bit */
-    enum decorrelation_type decorrelation;
+    enum decorrelation_type decorrelation;  ///< channel decorrelation type in the current frame
 
-    int32_t *decoded[MAX_CHANNELS];
+    int32_t *decoded[MAX_CHANNELS];         ///< decoded samples
     uint8_t *bitstream;
     unsigned int bitstream_size;
     unsigned int bitstream_index;